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To produce expandable graphite, natural graphite flakes are treated in a bath of acid and oxidizing agent.Usually used oxidizing agents are hydrogen peroxide, potassium permanganate or chromic acid. Concentrated sulphuric acid or nitric acid are usually used as the compound to be incorporated, with the reaction taking place at temperatures of ...
The expanded graphite can be used to make graphite foil or used directly as a "hot top" compound to insulate molten metal in a ladle or red-hot steel ingots and decrease heat loss, or as firestops fitted around a fire door or in sheet metal collars surrounding plastic pipe (during a fire, the graphite expands and chars to resist fire ...
Using paper-making techniques on dispersed, oxidized and chemically processed graphite in water, monolayer flakes form a single sheet and create strong bonds. These sheets, called graphene oxide paper, have a measured tensile modulus of 32 GPa. [8] The chemical property of graphite oxide is related to the functional groups attached to graphene ...
Graphene oxide paper or graphite oxide paper is a material fabricated from graphite oxide. Micrometer thick films of graphene oxide paper are also named as graphite oxide membranes (in the 1960s) or (more recently) graphene oxide membranes. The membranes are typically obtained by slow evaporation of graphene oxide solution or by the filtration ...
Rosalind Franklin first identified them in a 1951 paper in Proceedings of the Royal Society. [1] In this paper, she defined graphitizing carbons as those that can transform into crystalline graphite by being heated to 3,000 °C (3,270 K; 5,430 °F), while non-graphitizing carbons do not transform into graphite at any temperature.
Hummers' method is a chemical process that can be used to generate graphite oxide through the addition of potassium permanganate to a solution of graphite, sodium nitrate, and sulfuric acid. It is commonly used by engineering and lab technicians as a reliable method of producing quantities of graphite oxide.
Potassium graphite under argon in a Schlenk flask. A glass-coated magnetic stir bar is also present. One of the best studied graphite intercalation compounds, KC 8, is prepared by melting potassium over graphite powder. The potassium is absorbed into the graphite and the material changes color from black to bronze. [3]
Structure proposed in 1998 [1] with functional groups. A: Epoxy bridges, B: Hydroxyl groups, C: Pairwise carboxyl groups. Graphite oxide (GO), formerly called graphitic oxide or graphitic acid, is a compound of carbon, oxygen, and hydrogen in variable ratios, obtained by treating graphite with strong oxidizers and acids for resolving of extra metals.